1. Field of Invention
This invention relates to portable foldable canopy supports.
2. Prior Art
Numerous forms of structure for supporting canopies which provide shelter from the natural elements such as sunlight or rain have been invented. The most well known type of canopy structure is that of the umbrella or parasol. However, the centrally supported foldable rib and cloth structure of the familiar parasol or umbrella does not suit all shelter environments. The circular canopy does not effectively shelter rectangular areas, the mushroom shape is vulnerable to gusts of wind and it is often impractical to provide a support connection at the center of the area to be sheltered.
Others have invented canopy structures which avoid some of the disadvantages of the umbrella or parasol. U.S. Pat. No. 4,865,381 to Van Rogue discloses "A Sunshade Attachment" for a chair constructed from an assembly of U-shaped members. The sunshade covers a rectangular area and fastens to the back of a chair, attached via one of the U-shaped members. U.S. Pat. No. 4,781,411 to Kolb discloses a "Portable Sun Shield" made from plastic piping. This shield is substantially rectangular, and is cantilever-supported at the center of one of the sides of the rectangle by means of a vertical mast. The supporting structure can be separated into two major segments to make it more portable. U.S. Pat. No. 2,821,204 to Hartshorn, Sr. discloses a rectangular rib and cloth style canopy demountably attached to a boat. The supporting ribs are centrally held under the canopy by a tubular bar which projects as a cantilevered member from a vertical mast positioned outside the perimeter of the canopy. These disclosures argue the need for the rectangular shape, and provide canopy designs which are portable and more adaptable to wind conditions than an umbrella. They have a means for supporting the canopy above a solid base object which is not disposed directly under the area of the canopy.
Prior art does not satisfy the need for a structure that can selectively shelter rectangular areas at an adjustable height. The above patent disclosures do not describe a compactly foldable canopy support which holds all the members parallel and interconnected in the folded state. The above disclosures do not show how to make a canopy support that can have up to four independently foldable rectangular canopy segments integral with the canopy support.